Degradation of Proteoglycans and Collagen in Equine Meniscal Tissues.

Investigate meniscal extracellular matrix degradation. Equine menisci (n = 34 from 17 horses) were studied. Site-matched sections were cut and scored from three regions (ROIs; n = 102) and stained for histology, proteoglycan (safranin O and fast green), aggrecan, and collagen cleavage (NITEGE, DIPEN, and C1,2C antibodies, respectively). Picrosirius red and second harmonic generation microscopy were performed to investigate collagen ultrastructure. A total of 42 ROIs met the inclusion criteria and were included in the final analysis. The median (range) ROI histological score was 3 (0-9), providing a large spectrum of pathology. The median (range) proteoglycan score was 1 (0-3), representing superficial and central meniscal loss. The median (range) of DIPEN, NITEGE, and C1,2C scores was 1 (0-3), revealing immunostaining of the femoral and tibial surfaces. The proteoglycan scores exhibited significant positive associations with both histologic evaluation (p = 0.03) and DIPEN scores (p = 0.02). Additionally, a robust positive association (p = 0.007) was observed between the two aggrecanolysis indicators, NITEGE and DIPEN scores. A negative association (p = 0.008) was identified between NITEGE and histological scores. The C1,2C scores were not associated with any other scores. Picrosirius red and second harmonic generation microscopy (SHGM) illustrated the loss of the collagen matrix and structure centrally. Proteoglycan and collagen degradation commonly occur superficially in menisci and less frequently centrally. The identification of central meniscal proteoglycan and collagen degradation provides novel insight into central meniscal degeneration. However, further research is needed to elucidate the etiology and sequence of degradative events.

Vascularity evaluation of the equine tarsocrural and proximal intertarsal joint septum, and comparative analysis of two arthroscopic transection techniques.

OBJECTIVE: To evaluate vascularity of the synovial membrane covered septum (SMS) separating the tarsocrural (TC) and proximal intertarsal (PIT) joints (Part 1) and compare two methods of transection, electrosurgical or Ferris Smith rongeur (FS rongeur) (Part 2). STUDY DESIGN: Experimental study. SAMPLE POPULATION: Part 1, 10 SMS (n = 5 horses). Part 2, six horses (n = 12 tarsi). METHODS: In part 1, SMS harvested postmortem were each divided into eight regions of interest (ROIs), processed for histology, and immunostained with anti-α-actin antibody for blood vessel identification. Vascular density was calculated for each ROI. Data was compared within and between horses. In part 2, six horses underwent TC arthroscopy. Each limb was randomly assigned to undergo either electrosurgical or FS rongeur SMS transection. SMS transection and total operative time were recorded. Intraoperative hemorrhage was scored. Data was compared between both techniques. RESULTS: Significant interindividual variations in SMS vascular density were detected (p = .02), but there were no differences among ROIs. No differences in the transection time were detected between electrosurgery (4.83 ± 0.54 min) and FS rongeur (4.33 ± 0.67 min). No differences were found in intraoperative hemorrhage scores between techniques. CONCLUSION: Vascularity within the SMS varies among horses but not within its regions. Electrosurgical or FS rongeur transection of the medial SMS during tarsocrural arthroscopy is a rapid technique and improves surgical access to the dorsal compartment of the PIT.

Intervention of pharmacist included in multidisciplinary team to reduce adverse drug event: a qualitative systematic review.

BACKGROUND: Preventable harm in healthcare is a growing public health challenge. In addition to the economic costs of safety failures, adverse drug events (ADE) may lead to complication or even death. Multidisciplinary care team involving a pharmacist appears to be an adequate response to prevention of adverse drug event. This qualitative systematic review aims to identify and describe multidisciplinary planned team-based care involving at least one pharmacist to limit or prevent adverse drug events in the adult patients. METHODS: To determine the type of interprofessional collaboration to prevent adverse drug event in which a pharmacist was involved, we conducted a qualitative systematic review of the literature of randomized controlled trials. Two independent reviewers screened trials in three databases: Medline, Web of Science, ScienceDirect. Prospective studies of at least three different health professionals' interventions, one of whom was a pharmacist in the last five years were included. Two reviewers performed data extraction and quality appraisal independently. We used TIDieR checklist to appraise articles quality. RESULTS: In total 803 citations were retrieved, 34 were analysed and 16 full-text articles were reviewed. Only 3 studies published an implementation evaluation. More than half of the interventions (62%) targeted elderly patients including 6 whom lived in nursing homes. Studies outcomes were heterogeneous, and we did not perform a statistical analysis of the impact of these interventions. Most teams are composed of a physician/pharmacist/nurse trio (94%; 100%; 88%). Half of the teams were composed of the primary care physician. Other professionals were included such as physical therapists (25%), social worker (19%), occupational therapists (12%), and community health educator (6%). Multidisciplinary medication review was the most common intervention and was generally structured in four steps: data collection and baseline assessment, appraisal report by health professionals, a multidisciplinary medication review meeting and a patient follow-up. CONCLUSIONS: The most common multidisciplinary intervention to prevent ADE in the adult population is the multidisciplinary drug review meeting at least the physician/pharmacist/nurse trio. Interventions target mostly elderly people in nursing homes, although complex chronic patients could benefit from this type of assessment. TRIAL REGISTRATION: PROSPERO registration: CRD42022334685.

Regulation of carbon metabolism in two maize sister lines contrasted for chilling tolerance.

Maize can grow in cool temperate climates but is often exposed to spring chilling temperatures that can affect early seedling growth. Here, we used two sister double-haploid lines displaying a contrasted tolerance to chilling to identify major determinants of long-term chilling tolerance. The chilling-sensitive (CS) and the chilling-tolerant (CT) lines were grown at 14 °C day/10 °C night for 60 d. CS plants displayed a strong reduction in growth and aerial biomass compared with CT plants. Photosynthetic efficiency was affected with an increase in energy dissipation in both lines. Chilling tolerance in CT plants was associated with higher chlorophyll content, glucose-6-phosphate dehydrogenase activity, and higher sucrose to starch ratio. Few changes in cell wall composition were observed in both genotypes. There was no obvious correlation between nucleotide sugar content and cell wall polysaccharide composition. Our findings suggest that the central starch-sucrose metabolism is one major determinant of the response to low temperature, and its modulation accounts for the ability of CT plants to cope with low temperature. This modulation seemed to be linked to a strong alteration in the biosynthesis of nucleotide sugars that, at a high level, could reflect the remobilization of carbon in response to chilling.

Development of a computer-based quantification method for immunohistochemically-stained tissues and its application to study mast cells in equine wound healing (proof of concept).

BACKGROUND: There is a growing interest in the scientific community to use computer-based software programs for the quantification of cells during physiological and pathophysiological processes. Drawbacks of computer-based methods currently used to quantify immunohistochemical staining are the complexity of use, expense of software and overly-simplified descriptions of protocol thereby limiting reproducibility. The precise role of mast cells in equine cutaneous wound healing is unknown. Given the contribution of mast cells to the chronic inflammation observed in human keloid, a pathology similar to exuberant granulation tissue (EGT) in horses, mast cells might be present in high numbers in equine limb wounds predisposed to EGT. The main goal of this study was to develop a reliable and reproducible quantification method for immunostained tissues using a computer software that is widely available, at no cost, to the scientific community. A secondary goal was to conduct a proof of concept using the newly-established method to quantify mast cells during wound healing at different anatomical sites (body and limb) in horses to see if a different pattern is observed in limb wounds, which are predisposed to EGT. RESULTS: A good intraclass correlation coefficient (ICC, 0.67 p < 0.05) was found between the computer-based ImageJ method and manual counting. An excellent intra-operator ICC of 0.90 (p < 0.01) was found for the ImageJ quantification method while a good interoperator ICC of 0.69 (p < 0.01) was measured. No significant difference was observed between the variation of the ImageJ and that of the manual counting method. Mast cells were localized below the epidermis, around cutaneous appendages and blood vessels. Mast cell numbers did not differ significantly in relation to anatomical location or time of healing. CONCLUSIONS: The computer-based quantification method developed is reliable, reproducible, available, cost-free and could be used to study different physiological and pathological processes using immunohistochemistry.

Impact of a preoperative pharmaceutical consultation in scheduled orthopedic surgery on admission: a prospective observational study.

BACKGROUND: Medication errors have a high prevalence in surgery and management of home medication is strongly involved in these errors. In scheduled surgery, the preoperative consultation is a privileged time to inform the patient about the management of her/his home medication before admission. This study assessed the impact of a pre-anesthesia best possible medication history (PA-BPMH) on admission. The PA-BPMH was performed by a clinical pharmacist prior to the anesthesia consultation for anesthesiologists to prescribe admission medical orders for scheduled orthopedic surgery patients. METHODS: This was a prospective observational study which was carried out in an orthopedic surgery department. All patients over 18 years old with an elective orthopedic surgery were eligible except ambulatory surgery patients. The pharmacist registered the PA-BPMH into the software making it available for anesthesiologists for the pre-admission medication order. Finally, a medication reconciliation was performed at admission. The main outcome was the percentage of patients with at least one unintended medication discrepancy (UMD) at admission. The nature, potential clinical impact and acceptance rate of each UMD detected were assessed. Also, the PA-BPMH process was described and patients and anesthesiologists satisfaction was evaluated. RESULTS: A total of 455 patients had a pharmaceutical consultation. Medication reconciliation was performed at admission for 360 patients. Overall, at least one UMD was observed in 13.0% of patients (n = 47). A total of 63 UMD were detected. The most common type of UMD was omission (25.4%) and incorrect drug (23.8%).Two UMD (3.2%) were evaluated as life threatening. All the UMD detected were corrected on the admission medication order. CONCLUSION: A preoperative pharmacist-anesthesiologist teamwork seems to improve the safety of perioperative management of home medication for scheduled orthopedic surgery patients. This process needs a randomized clinical trial across a wider range of surgeries before its implementation.

The Impact of Collagen Fibril Polarity on Second Harmonic Generation Microscopy.

In this work, we report the implementation of interferometric second harmonic generation (SHG) microscopy with femtosecond pulses. As a proof of concept, we imaged the phase distribution of SHG signal from the complex collagen architecture of juvenile equine growth cartilage. The results are analyzed in respect to numerical simulations to extract the relative orientation of collagen fibrils within the tissue. Our results reveal large domains of constant phase together with regions of quasi-random phase, which are correlated to respectively high- and low-intensity regions in the standard SHG images. A comparison with polarization-resolved SHG highlights the crucial role of relative fibril polarity in determining the SHG signal intensity. Indeed, it appears that even a well-organized noncentrosymmetric structure emits low SHG signal intensity if it has no predominant local polarity. This work illustrates how the complex architecture of noncentrosymmetric scatterers at the nanoscale governs the coherent building of SHG signal within the focal volume and is a key advance toward a complete understanding of the structural origin of SHG signals from tissues.

Behavioral and psychological symptoms of dementia: how long does every behavior last, and are particular behaviors associated with PRN antipsychotic agent use?

Behavioral and psychological symptoms of dementia (BPSD) affect approximately all residents in nursing homes at some point; however, the course of BPSD among this group is not well known. The goal of the current study was to describe the course of each measured BPSD over a period of 6 months. A secondary explorative objective was to identify which BPSD are associated with as-needed (PRN) antipsychotic drug use. This secondary analysis study of 146 nursing home residents was drawn from a prospective, observational, multisite (N = 7) cohort study. Results showed that BPSD lasted for an average of 2.3 months, and the BPSD saying things that do not make sense had the longest duration, with 3.6 months. PRN antipsychotic drug administration was associated with nocturnal BPSD and requesting help unnecessarily. Within 3 months, most BPSD were resolved by usual care; use of PRN antipsychotic medication was not associated with behaviors that put the residents or their caregivers at risk.

In vitro stability of low-concentration ziconotide alone or in admixtures in intrathecal pumps.

OBJECTIVES: Ziconotide is often administered in combination with other analgesics via an intrathecal pump. Studies have established that ziconotide is stable when delivered alone in high concentrations. No stability data are available, however, for ziconotide given in low concentrations and/or with other analgesics as usually occurs in clinical oncology practice. The objective of this study was to assess the in vitro stability of ziconotide alone and combined with other analgesics in intrathecal pumps at 37 °C, as well as in syringes at 5 °C, to evaluate conditions for storing and transporting preparations. MATERIALS AND METHODS: Various ziconotide concentrations (0.1, 0.25, 0.5, and 0.75 µg/mL) were combined with an admixture of ropivacaine (7.5 mg/mL), morphine (7.5 mg/mL), and clonidine (15 µg/mL) in 20-mL intrathecal pumps at 37 °C and in syringes at 5 °C. Solutions of ziconotide alone in concentrations of 0.25, 0.5, 0.75, and 1 µg/mL were introduced into pumps at 37 °C and syringes at 5 °C. Assays were performed using ultra high pressure liquid chromatography. RESULTS: In admixtures, mean ziconotide concentrations decreased linearly to 53.4% (± 3.33%) of baseline after 35 days. When ziconotide was introduced alone in pumps at 37 °C, the residual concentration on day 31 was 35.54% (± 0.04%) with 0.25 µg/mL, 39.37% (± 0.15%) with 0.5 µg/mL, and 44.49% (± 0.18%) with 1 µg/mL. Ziconotide alone or combined with the other analgesics was stable in syringes stored at 5 °C. The preparations complied with the prescriptions, with a mean error of less than 10%, except with the lowest ziconotide concentration (0.1 µg/mL). CONCLUSIONS: At the low ziconotide concentrations studied, the degradation of ziconotide admixed with other drugs was linear and only weakly influenced by the baseline concentration. Linear regression with intrapolation to 30 days showed that the degradation of ziconotide admixed with other drugs was consistent with previously published data.

Micro-computed tomography reveals high-density mineralised protrusions and microstructural lesions in equine stifle joint articular cartilage.

BACKGROUND: Stifle osteoarthritis (OA) lesions are most common in the medial femorotibial (MFT) compartment. Their characterisation and mapping will inform equine veterinarians towards an accurate diagnosis of OA. OBJECTIVES: Investigate and map micro-CT (µCT) changes in the hyaline articular cartilage (HAC) in the medial femoral condyle (MFC) and medial tibial plateau (MTP). STUDY DESIGN: Ex vivo cadaveric. METHODS: Stifles (n = 7 OA and 17 control [CO]) were retrieved from a tissue bank. The MFC and MFT were imaged with µCT. Regions of interest (ROIs) were cranial (MFCcr; MTPcr) and caudal (MFCca; MTPca) sites. In each ROI, µCT images were scored for HAC fibrillation, surface mineralisation and for the presence of high-density mineralised protrusions (HDMP). The lesions were mapped, and site-matched histology was performed. RESULTS: The microstructure of healthy and abnormal HAC was discernible on µCT images and confirmed with histology. HAC fibrillation was more prevalent (p = 0.019) in the MFCcr of the OA group (n = 7/7, 100%) when compared with the CO group (n = 7/17, 41%). Score 1 HAC surface mineralisation was more prevalent (p = 0.038) in the OA MFCca (n = 4/7, 57%) when compared with the CO group (n = 2/17, 12%). HDMP were heterogenous and hyperdense mineralised material protruding into the HAC and were more frequent (p = 0.033) in MFCs (n = 12/24, 50%) compared with MTPs (n = 5/24, 20%). Score 3 HDMPs were also more prevalent (p = 0.003) in the MFCcr (n = 7/24, 29%) compared with MFCca (n = 0/24, 0%) and in MFCs (n = 7/24, 29%) compared with MTPs (n = 3/24, 12.5%) (p = 0.046). MAIN LIMITATIONS: Clinical history was not available for all specimens. CONCLUSIONS: Equine HDMP and HAC surface mineralisation are imaged for the first time in the MFT joint. HAC fibrillation and erosion and HDMP are more frequent in the cranial aspect of the MFC. µCT images of OA in equine stifle joints provide a novel perspective of lesions and improve understanding of OA.

Characterization and quantification of in-vitro equine bone resorption in 3D using µCT and deep learning-aided feature segmentation.

High cyclic strains induce formation of microcracks in bone, triggering targeted bone remodeling, which entails osteoclastic resorption. Racehorse bone is an ideal model for studying the effects of high-intensity loading, as it is subject to focal formation of microcracks and subsequent bone resorption. The volume of resorption in vitro is considered a direct indicator of osteoclast activity but indirect 2D measurements are used more often. Our objective was to develop an accurate, high-throughput method to quantify equine osteoclast resorption volume in µCT 3D images. Here, equine osteoclasts were cultured on equine bone slices and imaged with µCT pre- and postculture. Individual resorption events were then isolated and analyzed in 3D. Modal volume, maximum depth, and aspect ratio of resorption events were calculated. A convolutional neural network (CNN U-Net-like) was subsequently trained to identify resorption events on post-culture µCT images alone, without the need for pre-culture imaging, using archival bone slices with known resorption areas and paired CTX-I biomarker levels in culture media. 3D resorption volume measurements strongly correlated with both the CTX-I levels (p < 0.001) and area measurements (p < 0.001). Our 3D analysis shows that the shapes of resorption events form a continuous spectrum, rather than previously reported pit and trench categories. With more extensive resorption, shapes of increasing complexity appear, although simpler resorption cavity morphologies (small, rounded) remain most common, in acord with the left-hand limit paradigm. Finally, we show that 2D measurements of in vitro osteoclastic resorption are a robust and reliable proxy.

Radiographic analysis in Thoroughbreds reveals morphological changes in healthy maturing stifle joints and possible association between subchondral lesions and femoral condyle width.

OBJECTIVE: Assess femorotibial features in foals with and without medial femoral condyle (MFC) subchondral radiolucencies (SR+ and SR-). METHODS: 3 independent, sequential radiographic studies were performed. Study 1 retrospectively measured femorotibial morphological parameters in repository radiographs (SR- and SR+). Study 2 qualitatively compared drawings of intercondylar notch shape in postmortem radiographs (SR-). Study 3 prospectively measured femorotibial parameters in 1-month-old foals (SR-). In studies 1 and 3, 13 morphologic parameters were measured. Limb directional asymmetry was assessed in 2 age groups (< 7 or ≥ 7 months). RESULTS: Study 1 (SR- group; n = 183 radiographs) showed increased femoral measurements with maturation, except the distal femoral intercondylar notch width (FINwal), which decreased. In contrast, in SR+ stifles (53 radiographs), 3 femoral parameters (MFC width [MFCwpf], MFC height, or FINwal) showed no changes. Tibial plateau width alone increased with maturation in both groups. Interobserver reliability was good to excellent. Study 2 (n = 53 radiographs) confirmed a distal FINw decrease in SR- foals. In study 1, left SR- stifles in greater than or equal to 7-month-old fillies had significantly larger femoral bicondylar width and FINw, while right SR+ stifles in fillies greater than or equal to 7 months had a significantly larger MFCw. In study 3 of 1-month-old foals (n = 94 SR- radiographs), the MFCw, femoral condyle bicondylar width, and lateral femoral condyle height were all greater on the left, whereas the intercondylar intereminence space width was larger on the right. CLINICAL RELEVANCE: In SR+ stifles, the distal femur exhibited divergent maturation, indicating a wider MFC in the right stifle in older foals. As SR lesions are more common on the right, this suggests a potential association with MFC morphology.

An in vitro model for discovery of osteoclast specific biomarkers towards identification of racehorses at risk for catastrophic fractures.

BACKGROUND: Focal bone microcracks with osteoclast recruitment and bone lysis, may reduce fracture resistance in racehorses. As current imaging does not detect all horses at risk for fracture, the discovery of novel serum biomarkers of bone resorption or osteoclast activity could potentially address this unmet clinical need. The biology of equine osteoclasts on their natural substrate, equine bone, has never been studied in vitro and may permit identification of specific biomarkers of their activity. OBJECTIVES: (1) Establish osteoclast cultures on equine bone, (2) Measure biomarkers (tartrate resistant acid phosphatase isoform 5b [TRACP-5b] and C-terminal telopeptide of type I collagen [CTX-I]) in vitro and (3) Study the effects of inflammation. STUDY DESIGN: In vitro experiments. METHODS: Haematopoietic stem cells, from five equine sternal bone marrow aspirates, were differentiated into osteoclasts and cultured either alone or on equine bone slices, with or without a pro-inflammatory stimulus (IL-1ß or LPS). CTX-I and TRACP-5b were immunoassayed in the media. Osteoclast numbers and bone resorption area were assessed. RESULTS: TRACP-5b increased over time in osteoclast cultures without bone (p < 0.0001) and correlated with osteoclast number (r = 0.63, p < 0.001). CTX-I and TRACP-5b increased with time for cultures with bone (p = 0.002; p = 0.02 respectively), correlated with each other (r = 0.64, p < 0.002) and correlated with bone resorption (r = 0.85, p < 0.001; r = 0.82, p < 0.001 respectively). Inflammation had no measurable effects. MAIN LIMITATIONS: Specimen numbers limited. CONCLUSIONS: Equine osteoclasts were successfully cultured on equine bone slices and their bone resorption quantified. TRACP-5b was shown to be a biomarker of equine osteoclast number and bone resorption for the first time; CTX-I was also confirmed to be a biomarker of equine bone resorption in vitro. This robust equine specific in vitro assay will help the study of osteoclast biology.

Cannabinoid receptors are expressed in equine synovium and upregulated with synovitis.

BACKGROUND: Osteoarthritis (OA) is a major cause of equine lameness. Cannabinoid (CB) receptors are now considered to be promising therapeutic targets in human rheumatology for pain and inflammation, however, little is known about the equine endocannabinoid system. OBJECTIVES: The primary goal was to assess the presence and expression pattern of CB1 and CB2 in the synovium of healthy joints. A secondary goal was to explore the relationship between the CB expression, degree of synovitis and OA pathology. STUDY DESIGN: Ex vivo experimental study. METHODS: Metacarpophalangeal joints (n = 25) from a tissue bank were studied. The joints were dissected, and the articular cartilage lesions were scored. Synovial membrane specimens (n = 45) were harvested, fixed and the degree of synovitis was graded on histological sections. Colocalised synovial sections were also immunostained with antibodies to CB1 and CB2. Five regions of interest were randomly selected from digital images of manually segmented synovial intima and scored blindly for positive cellular immunoreactive staining by two independent observers. Interobserver agreement was calculated with an intraclass correlation coefficient (ICC). Relationships between CB1 and CB2 immunoreactive scores and synovitis or joint OA grade were explored with mixed linear models. RESULTS: CB1 was expressed in synovial intimal cells in all specimens studied whereas CB2 expression was identified in 94%. Both receptors were also expressed in the subintimal blood vessel walls. ICCs were 84.6% (CB1) and 92.9% (CB2) for the immunoreactivity scores. Both CB1 and CB2 expression were significantly upregulated (p = 0.04 and p = 0.03, respectively) with increasing degree of synovitis. Conversely, CB1 expression significantly decreased (p = 0.03) with increasing severity of OA. MAIN LIMITATIONS: The type of synovial cell expressing CB1 or CB2 was not investigated. CONCLUSION: Equine synovial intimal cells constitutively express both CB1 and CB2 receptors that are upregulated with synovitis and may have a role in joint pain. They are potential targets for therapy with cannabinoid molecules or their derivatives.

In vivo effects of a single intra-articular injection of 2% lidocaine or 0.5% bupivacaine on articular cartilage of normal horses.

OBJECTIVE: To assess the effects of an intra-articular (IA) lidocaine or bupivacaine injection on synovial fluid (SF) biomarkers of cartilage metabolism. STUDY DESIGN: Experimental. ANIMALS: Horses (n = 6). METHODS: The study had 2 components, each with an identical design: the first arm assessed the effects of bupivacaine (0.5%) IA in the intercarpal joints and, after a 2-week washout period, the second was conducted to evaluate the effects of IA lidocaine (2%) in the tarsocrural joints. The mares were randomly assigned to receive the test local anesthetic in the target joint or the placebo (0.9% NaCl) in the contralateral joint. After a 2-week washout period, treatments were reversed, yielding 6 joints for each treatment. SF samples were collected for measurement of biomarkers of cartilage metabolism. RESULTS: IA bupivacaine or lidocaine induced a significant increase in both markers of cartilage matrix synthesis (CS846-aggrecan and CPII-type II collagen) suggesting an anabolic effect. Bupivacaine also resulted in an unanticipated decrease in both collagen degradation markers (C2C and C1,2C). CONCLUSIONS: These results reveal an anabolic effect of single IA injections of local anesthetics on cartilage metabolism. Although collagen degradation biomarker results were not increased, it is possible that the anabolic response is because of an undetected cartilage insult, and requires further investigation.

Microstructural features of subchondral radiolucent lesions in the medial femoral condyle of juvenile Thoroughbreds: A microcomputed tomography and histological analysis.

BACKGROUND: The aetiology of equine medial femoral condyle (MFC) subchondral bone radiolucencies (SR) is unknown. OBJECTIVES: Characterise the microstructural structural features of MFC SR in juvenile Thoroughbreds with microcomputed tomography (µCT) and histology. STUDY DESIGN: Cross-sectional post-mortem study. METHODS: Distal femurs were collected at post-mortem. Conventional tomodensitometry was employed to scout for MFCs with and without SR lesions (SR+ and SR-, respectively). Group 1 were CT MFC SR+ and Group 2 age-matched SR- controls. Both underwent µCT and histological analysis. Group 3 CT MFC SR- foals, <6 months, were selected to search for chondronecrosis. Histological sections, processed from the lesion (Group 1) and a corresponding site in Groups 2 and 3, were assessed for chondronecrosis, fibrin, fibroplasia and osteochondral separation. Group 3 sections were surveyed for chondronecrosis alone. RESULTS: A total of 178 femurs from 89 Thoroughbreds were harvested. Of these horses 19.1% (95% CI: 10.9%-27.3%) were CT MFC SR+ (17/23; 7.46 ± 4.36 months) and met the inclusion criteria for Group 1. Group 2 included 30 CT MFC SR- specimens (5.00 ± 2.73 months) and Group 3 had 44 CT MFC SR- s (2.68 ± 1.74 months). SR were located axially in foals <7 months of age, and centrally thereafter. All SRs had areas of thickened cartilage on histology and separation at the osteochondral junction containing fibrin (acute event) and fibroplasia (chronicity) in 73.9% (17/23; 95% CI: 56%-91.9%). In Group 1 specimens, chondronecrosis was present in 82.6% (19/23; 95% CI: 67.1%-98.1%) but four MFC SR+ had no evidence of chondronecrosis. Chondronecrosis was not detected in the Group 3 foal MFCs. MAIN LIMITATIONS: No longitudinal follow-up. CONCLUSIONS: The absence of chondronecrosis, pathognomic of osteochondrosis, in four MFC SR+s and in all of the CT MFC SR- foals suggests that osteochondrosis is not the cause, or the only cause, of these lesions and favours trauma as an alternate aetiological hypothesis.

Osteoclast density is not increased in bone adjacent to radiolucencies (cysts) in juvenile equine medial femoral condyles.

BACKGROUND: There is a knowledge gap about how equine MFC subchondral radiolucencies (SR) arise and evolve. Osteoclasts are believed to have a role but have not been studied in situ. OBJECTIVES: To measure and compare osteoclast density and the percentage of chondroclasts in healthy and MFC SR specimens from juvenile Thoroughbreds. STUDY DESIGN: Cadaveric study. METHODS: Medial femoral condyles (MFC) from a tissue bank of equine stifles were studied. Inclusion criteria were MFCs (≤8 months old) with a computed tomography SR lesion and histological focal failure of endochondral ossification (L group). Contralateral, lesion-free, MFCs were a control group (CC). Osteochondral slabs were cut through the lesion (L), a healthy site immediately caudal to the lesion, (internal control; IC) and the contralateral, site-matched controls (CC). Histological sections were immunostained with Cathepsin K for osteoclast counting. Osteoclasts in contact with the growth cartilage (chondroclasts) were also counted. The sections were segmented into regions of interest (ROI) at different depths in the subchondral bone: ROI1 (0-1 mm), ROI2 (1-3 mm) and ROI3 (3-6 mm). Osteoclasts were counted and the bone area was measured in each ROI to calculate their density. Chondroclasts were counted in ROI1 . RESULTS: Sections were studied from L and IC (n = 6) and CC sites (n = 5). Osteoclast density was significantly higher in ROI1 when compared with ROI3 in all groups. Although higher osteoclast density was measured in ROI1 in the L group, no significant differences were detected when compared with control ROIs. The proportion of chondroclasts in ROI1 was lower in the L sections when compared with controls but no significant differences were detected. MAIN LIMITATIONS: Limited sample size. CONCLUSIONS: Osteoclasts are important actors in MFC subchondral bone development, digesting both growth cartilage (chondroclasts) and bone, but the pathophysiology of early MFC SRs cannot be explained solely by an increased osteoclast presence in the subchondral bone.

The maize low-lignin brown midrib3 mutant shows pleiotropic effects on photosynthetic and cell wall metabolisms in response to chilling.

Maize (Zea mays L.) is one of the major cereal crops in the world and is highly sensitive to low temperature. Here, changes in photosynthetic and cell wall metabolisms were investigated during a long chilling exposure in inbred line F2 and a low-lignin near-isogenic brown midrib3 mutant (F2bm3), which has a mutation in the caffeic acid O-methyltransferase (COMT) gene. Results revealed that the plant biomass was reduced, and this was more pronounced in F2bm3. Photosynthesis was altered in both lines with distinct changes in photosynthetic pigment content between F2bm3 and F2, indicating an alternative photoprotection mechanism between lines under chilling. Starch remobilization was observed in F2bm3 while concentrations of sucrose, fructose and starch increased in F2, suggesting a reduced sugar partitioning in F2. The cell wall was altered upon chilling, resulting in changes in the composition of glucuronorabinoxylan and a reduced cellulose level in F2. Chilling shifted lignin subunit composition in F2bm3 mutant to a higher proportion of p-hydroxyphenyl (H) units, whereas it resulted in lignin with a higher proportion of syringyl (S) residues in F2. On average, the total cell wall ferulic acid (FA) content increased in both genotypes, with an increase in ether-linked FA in F2bm3, suggesting a greater degree of cross-linking to lignin. The reinforcement of the cell wall with lignin enriched in H-units and a higher concentration in cell-wall-bound FA observed in F2bm3 as a response to chilling, could be a strategy to protect the photosystems.

Impact of a pharmacist and geriatrician medication review on drug-related problems in older outpatients with cancer.

OBJECTIVES: Older patients with cancer have increased risk for comorbidity, polypharmacy (PP) and drug related problems (DRP). The aim of this study was to assess the effect of a clinical pharmacist and geriatrician medication review (MR) among older outpatients with cancer to optimize management of comorbidities during comprehensive geriatric assessment (CGA). MATERIAL AND METHODS: We conducted a single-center prospective study among older outpatients with cancer (≥75 years). A pharmacist consultation was added into CGA process. The clinical pharmacist detected and assessed PP and DRP such as potentially inappropriate medications (PIM) according to the Laroche French list and STOPP criteria, START criteria and adverse drug events (ADE) risk. After a multidisciplinary MR, the proposals for prescription modification were sent to general practitioners (GPs). RESULTS: Fifty-one consenting patients were recruited between May 2016 and March 2017, with a median age of 83 years. Prevalence of PP was 80.4%. 165 DRP were detected among 86% patients (median number of DRP = 3.0): 19.4% were misuse, 43.6% underuse, and 37.0% overuse. A significant decrease was observed in prevalence of PIM use (Laroche: 31.4% versus 5.9%, p = 0.002), START criteria (66.7% to 5.9%; P < 0.001) and ADE score (4.0 before MR versus 2.0 after, p = 0.023). A trend was observed for a lower number of medications (10.0 versus 8.0, p = 0.092) and on STOPP criteria prevalence (56.9% versus 31.4%, p = 0.12). CONCLUSION: A clinical pharmacist and a geriatrician MR is effective to detect and reduce DRP in older outpatients with cancer.

Abundant osteoclasts in the subchondral bone of the juvenile Thoroughbred metacarpus suggest an important role in joint maturation.

BACKGROUND: The administration of bisphosphonate medications, which target osteoclastic-bone remodelling, to juvenile and adult racehorses is a matter of debate owing to concerns that these molecules remain bound to the bone-mineralised matrix and may interfere with subsequent bone growth, adaptation to exercise and healing of bone microdamage in equine athletes. Osteoclasts participate in endochondral ossification, subchondral bone remodelling and bone repair. There is a knowledge gap on the role of equine osteoclast biology in the growth and maturation of joint surfaces and this information is important to inform judicious bisphosphonate use. OBJECTIVES: Measure and compare the osteoclast density in the subchondral bone of Thoroughbred (TB) distal third metacarpi (McIII) at different sites, varying depths from the articular surface and with age (0-84 months). STUDY DESIGN: Ex vivo cadaveric study. METHODS: McIIIs from foals, yearlings and adults were collected, fixed in formaldehyde and stored at 4°C. Sections were cut from the lateral hemi-metacarpus, stained and scored for cartilage degeneration. Osteoclasts were counted on immunohistochemically (Cathepsin K) stained sections. Osteoclast density was compared in regions of interest (ROIs-the sagittal ridge, axial and abaxial condyle) and also at two depths (0-3 mm and 3-6 mm) into the subchondral bone below the osteochondral junction. RESULTS: The osteoclast density was consistently highest in the subchondral cortical bone plate (0-3 mm) when compared with the deeper trabecular bone in all age groups. Furthermore, the osteoclast density was significantly higher in juvenile Thoroughbreds (foals and yearlings) within both sites in the subchondral bone when compared with adults. MAIN LIMITATIONS: The number of specimens available for study was restricted. CONCLUSIONS: Osteoclasts are important in normal McIII epiphyseal and articular surface maturation and have a propensity to localise at the osteochondral junction and subchondral cortical bone plate zone in juvenile Thoroughbreds.